To evaluate choroidal thickness at the outside of the fovea in patients with diabetic retinopathy using spectral-domain optical coherence tomography.

We examined 87 eyes of 87 patients with diabetic retinopathy and 40 eyes of 40 normal patients. Patients with diabetic retinopathy were divided into 3 groups according to the grade of diabetic retinopathy and macular edema. The choroidal thickness was obtained at the fovea and outside of the fovea using enhanced depth imaging of Spectralis optical coherence tomography. One foveal and 8 peripheral images were selected and choroidal thickness was measured from the outer border of the retinal pigment epithelium to the inner scleral border.

Subfoveal choroidal thickness was thinner with increasing severity of diabetic retinopathy. However, there was no significant difference between groups without the nasal side of the fovea. A statistically significant difference was observed over the fovea at the superotemporal area.

The choroidal thickness outside of the fovea was thinner with the severity of diabetic retinopathy and was more pronounced in the superotemporal area.